ISO INTERNATIONAL STANDARD 356 Second edition ANsl Internat Doc Sec 1996-12-15 Essential oils - Preparation of test samples Huiles essentielles Preparation des échantillons pour essai ISO Reference number ISO 356:1996(E) No reproduction or networking permitted without license from IHS Not for Resale ISO356:1996(E) Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (IsO member bodies)., The work of preparing international Standards is normally carried out through isO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with IsO, also take part in the work. Iso collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. International Standard ISO 356 was prepared by Technical Committee 1SO/TC 54, Essential oils. This second edition cancels and replaces the first edition (IsO 356:1977), which has been technically revised. @1SO1996 Alf rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the publisher. International Organization for Standardization Case postale 56 . CH-1211 Geneve 20 : Switzerland Internet [email protected] X.400 C=ch; a=400net; p=iso; o=isocs; S=central PrintedinSwitzerland yright Intern Not for Resale ISO 356:1996(E) INTERNATIONALSTANDARD @ISO Essential oils - Preparation of test samples 1 Scope This International Standard gives general guidance for the preparation of samples of essential oils submitted to a laboratory for analysis. It is applicable, in particular, to those essential oils that cannot be analysed directly; that is those which are solid or partially solid at room temperature or those which are cloudy due to the presence of water or suspended particles. This method cannot be used for samples for determination of water. 2 Principle Filtration of the essential oil, if necessary liquefied by heating at a suitable temperature, after addition of magnesium sulfate or sodium suifate with a view to eliminating the water and the insoluble substances. 3 Apparatus Usual laboratory apparatus and, in particular, the following. 3.1 Oven. 3.2Conical flasks. 3.3 Suitable filtration equipment. 4 Reagent 4.1 Magnesium sulfate, recently desiccated and neutral or sodium sulfate, recently desiccated. To desiccate the magnesium sulfate or sodium sulfate, heat to a constant mass at 180 °C to 200 °C (temperature 5 Procedure 5.i Essentiai oiis which are solid or partialy solid at ambient temperature Liquefy the essential oil by placing it in the oven (3.1) maintained at the lowest temperature at which liquefaction During this operation, especially in the case of essential oils containing aldehydes, avoid allowing air to enter the container holding the essential oil. To achieve this, loosen, but do not remove, the stopper. Pour the liquefied theflask isfilledtonot morethantwo-thirds of its capacity. During all subsequent operations, the oil shall be kept at the lowest temperature at which it will remain liquid. Noreproductionornetworking pemited without licensefromIHS Not for Resale